In a conventional electronic pattern knitting machine used in knitting jacquard fabric, usually one course of the knitted fabric is knit on the basis of pieces of color information stored within the memory of the knitting machine. Pattern information commonly is transferred from a storage medium, such as a floppy disc or paper tape, through the software loading mechanism and to the knitting machine controller, which activates/deactivates the needle selection mechanisms. The needle selection mechanisms work in conjunction with yarn feeders, which selectively feed the desired color of yarn to the knitting needles. Much of the pattern information is resolved based on individual courses of a plurality of pieces of color information.
In one common electronic pattern knitting machine, one needle selection mechanism is selectable between two positions--knitting and welting (FIG. 6). In this type of machine, tucking is not performed. When knitting a single knit fabric, the yarn floats produced by welting extend between patterns of the same color on the reverse side of the knit fabric, and the resulting structure has a reduced commercial value. The floating yarns are not fixed within the single knit fabric as would be obtained if tuck knitting were performed. In improved knitting machines, in which tucking operations are possible to form a rugged surface, all needle selection information needed to form a jacquard fabric are not always available even when the information is derived directly from the conventional knitting machine mentioned above and applied to the controller of these improved knitting machines. These more complex machines are capable of three major methods enabling needle selection at the three positions of knitting, welting, and tucking (FIGS. 7, 8 and 9). As illustrated, one yarn feeder is controlled by pairs of yarn feed mechanisms 13,14; 16,17; and 19,20, all which Can have different functions and yet enable tucking. Each needle selection mechanism typically has two states and the combination of the mechanisms provides the diversity needed for enhanced jacquard knitting.
For example, in FIG. 7, one yarn feeder has two needle selection mechanisms 13,14 associated therewith. Needle selection for knitting or Welting is performed at needle selection unit 13, and needle selection for tucking or Welting is performed at needle selection unit 14. In FIG. 9, a different method is illustrated in which needle selection at three positions is performed by needle selection mechanisms 19 and 20, which are erected vertical to each other. In FIG. 8, another method is disclosed. Thus, it is difficult to compose pattern information for these improved knitting machines on the basis of color information used on the conventional electronic pattern knitting machines.